Parent command

Extended description

The command started using docker exec only runs while the container’s primary
process (PID 1) is running, and it is not restarted if the container is
restarted.

COMMAND will run in the default directory of the container. If the
underlying image has a custom directory specified with the WORKDIR directive
in its Dockerfile, this will be used instead.

COMMAND should be an executable, a chained or a quoted command
will not work. Example: docker exec -ti my_container "echo a && echo b" will
not work, but docker exec -ti my_container sh -c "echo a && echo b" will.

Examples

Run docker exec on a running container

First, start a container.

$ docker run --name ubuntu_bash --rm-i-t ubuntu bash

This will create a container named ubuntu_bash and start a Bash session.

Next, execute a command on the container.

$ docker exec-d ubuntu_bash touch /tmp/execWorks

This will create a new file /tmp/execWorks inside the running container
ubuntu_bash, in the background.

Next, execute an interactive bash shell on the container.

$ docker exec-it ubuntu_bash bash

This will create a new Bash session in the container ubuntu_bash.

Next, set an environment variable in the current bash session.

$ docker exec-it-eVAR=1 ubuntu_bash bash

This will create a new Bash session in the container ubuntu_bash with environment
variable $VAR set to “1”. Note that this environment variable will only be valid
on the current Bash session.

By default docker exec command runs in the same working directory set when container was created.

$ docker exec-it ubuntu_bash pwd
/

You can select working directory for the command to execute into

$ docker exec-it-w /root ubuntu_bash pwd
/root

Try to run docker exec on a paused container

If the container is paused, then the docker exec command will fail with an error: